The invention relates to a cleaning rod or implement for the bore of guns and, more particularly, to a flexible cleaning implement particularly adopted for insertion and operation in the breech end of airguns.
It is recognized in the airgun art that, despite the fact that there may be no obviously visible indication of dirt in the bore of an airgun, periodic and frequent cleaning of the bore is necessary. A dirty bore is one of the most insidious and significant factors in negatively affecting accuracy of an airgun.
Even though airguns do not get fouled by powder residue as firearms do, their bores are subjected to soft lead residue due to the shallow rifling of the bore and the soft lead used in the airgun pellets. These pellets can be badly deformed by deep rifling or grooves; furthermore, airguns do not generate the explosive power behind the pellet (as firearms do) to drive the pellet through deep rifling, so only very shallow rifling is used to give aerodynamic spin to the pellet. A residue of soft lead accumulates in the bore and rapidly affects the rifling.
Additionally, the bore is dirtied by a lubricant residue which is caused by a subtle form of compression ignition of minute portions of gun lubricants with each shot of a spring-piston airgun. This residue, although not necessarily corrosive, builds onto the lead fouling of the bore to further directly decrease target accuracy.
Although the cleaning of airgun bores need not be as frequent as required for fireamrs, the cleaning procedure is far more exacting and delicate due to the shallow rifling. Chemical solvents and conventional firearm bore cleaners cannot be used on airguns as they would destroy the breech seal and probably the piston seal, as well.
Rigid or solid cleaning rods are frequently used for insertion into the muzzle end of the airguns, although cleaning by insertion through the breech end of the gun would be more desirable and effective. Sometimes, a swivel handle is provided for these rods. Many airguns can't accept breech insertion of a solid cleaning rod, and cleaning is restricted to insertion at the muzzle end, which could seriously damage the muzzle crown or rifling. Some flexible solid rods in the form of spring-wire or plastic-coated spring-wire or solid synthetic resin have been used for muzzle insertion to project them through the breech, where cleaning pellets or patches are attached for withdrawal through the bore and out the muzzle end. All of the metallic cleaning rods, whether rigid or flexible, require protective bushings, stops or the like to prevent damage to the lands and grooves of the bore or to the crown.
In the style of airgun where the breech can be exposed and made fully accessible to a cleaning rod, such as in a single pump spring action gun where the barrel can be folded out of the way or in a bolt action gun where the bolt can be removed, the above-described cleaning rods can also be used for breech insertion, but ordinarily they are restricted to muzzle insertion. During breech insertion these rods tend to kink or break due to the acute entry angle required in the confined breech area.